Flame hardening apparatus



March 27, 1945. w. E. SMITH FLAME HARDENING APPARATUSV Filed Manch 14, 1941 7 Sheets-Sheet 1 LII .r

m an, No

' `1NVENTOR. WILLIAM E.SMITH.

March 27, 1945. w. E. sMlTH FLAME HARDENING APPARATUS 7 Sheets-Sheet 2 Filed March 14, 1941 WILITIAIVRTH.

March 27, 1945. w. SMlTH 2,372,298

FLAME HARDENING APPARATUS Filed Mal-0h14. 1941 v sheets-sheet s 'i ll il '1 d INVENTOR. WILLIAM E.SMITH.

March' 27, 1945. w. E. SMITH I 2,372,293

1 FLAME HARDENING APPARATUSl Filed March 14, 1941 'rsheets-sheqi 4 FIGA 'I INVENTOR. WILLIAMEMma,

March 27, 1945. w E SMH 2,372,298

FLAME HARDENING APPARATUS I Filed March 14, 1941 l '7 Sheets-Sheet 5 INVENTOR. WILLIAM.E SMITH.

March 27, 194.5.

w. E. sMli'l-i` FLAME HARDENING APPARATUS '7 Sheets-Sheet 5 Filed March 14, 1941 INVENTOR. WILLIAM 1:.sm'm.i

BY M

March 27, 1945. w. E. SMITH FLAME HARDNING APPARATUS Filed March 14, 1941 /f Kiln INVENTOR. WILLIAM E.$MlTH is guided by the work to vertically aswell as angularly or'in all three of a such directions simultaneously to follow any f torch structure mounted balanced upon a monorail track thereby to Patented Mir. 21, 194s s? 'PA'ifENT oi-Fica sans mais naltlmimvc.l msnarns n. smitmneinit.

Product.

)Rilland Steel niels.misn'erivrnev miic, a corporation ci (Hilo- Applicaties Muela-1i, mi, serial No. man

1'4 claim. (ci. zas-5)' This-invention relates to -new and provements in name hardening apparatus and the primary object of the invention is to provide apparatus in which-the llame hardening torch move horizontally and contour which the work piece may possess.

Another important object of the'invention is to provide an apparatus which will automatically follow any contour and angle of the work surface with the llame hardening .iets always at approximately 90 degrees to the surface of the work. l e e A further object of the invention is to provide a track as one arm of a pantograph which is guided to and iro by the'work piece and to provide a such track so that engagement of the torch with thework piece, causes both the torch and track to move relative to the workwhile the torch carl riage is being constantly propelled relative to the work. c

A furtherobiect 'of the invention is to provide in isuch an apparatus, a relative arrangement oi' parts whereby the torch carriage is substantially render -it exceedingly mobile over the work piece.

Still another object o! the invention is to proi vide the toren with a ymei supply conduit which inherently serves to maintainv the torch in the proper spaced relationship tothe work piece.

userul in,v

upon a carriage upon Another object of the invention is to provide improved constructions for the torches.

Other objects and advantages of the invention will become apparent during the course of the following description.

In the accompanying drawings forming a part ci the application and wherein like numerals are employed to designate like parts throughoutthe several views,

Fig. 1 is a front elevation of the llame hardening apparatus, Y

Fig.2isatopplanofthesame.

Fig. 3 is an end elevation of the same,

Fig. 4 is an enlarged elevation of the torch carrying carriage with parts thereof shown in section and with the torch engaging the work,

Fig. 5y is an elevation oi the torch head withon the line "iL- @if d,

ris. a is s anun-'section taxen sions tneiine HofFigJ, l -Fig. 9 is a transverse section taken along the line I-I oill'ig. '1,

Fig. l0 is a transverse' section taken along the line ll-Il of Fig. 8,

Fig. 11 is a the two torches on the 'lines lI-II voi! Figs. 9 .and 10,

-Fig. 12 is .a similar lines l2--I2ofPigs.9 and 10.

Fig. 13 is a similar section taken along the 4lines n-Is or risalenti 1o,

Fig. 14 is a transverse section taken along the `line 'IL-ll of Fig. '1, Y

Fig. 15 is a transverse section taken on theline is-II or Fig. 8, Fiss. 16 to 24 are views and sections of a modiged form of torch head to produce ribbon-like ames.

Pigs. 25 to 32 are views and sections of another modified form of torch head. A

This inventionprcvides an apparatus which v welding, name hardening or cutting operations 'along irregular lines or planes and requires no templates or ilxturesto provide for the path of movement o f the automatic apparatus, since the work itself provides such path. In addition, the torch will automatically-change its angle with the change of angle of the work without requiring stopping of theiapparatus and changing oi' tips. AIn all universal movements of the torch while it is traversing the entire length o! the work, the torch tips or jets vare maintained at an angle of `substantially 90 degrees to the work to be most effective. In order to require minimum universal movement of the torch, universally adjustable work holders are yprovided to permit positioning of thework so that the surfaces to be treated can be held to a line requiring the least shifting of the torch during its automatic travel. For this purpose, the bed of the apparatus is composed of a plurality of I beamsy l, transversely upon which are positioned a plurality of transverse I beams 2, superimposed upon which at right angles thereto are a plurality of equally spaced I beams 3, upon -any of which, at any points in the area ofthe may be employed for bed, may heclamped a -pair of work holders l at opposite ends thereof. Each work holder has an inverted T-shape piece l, upon the vertical stem of which is a vertically adjustable slide i, in which is mounted a horizontal pivot pin 'i for the pivotal suspension thereon of a. V-shaped work holding trough l. The work holding trough G icngitiminal section taken through section 'taken along the may be adjusted |9 to the desired about its axis 1, and held at the desired angle and elevation by a pair of set screws 9 extending through the slide 6 and engaging the uppermost end of the base of its stem, and by clamping bolts IU. The ends of a work piece are positioned in the trough shaped holders 8 at opposite sides of the bed and after the holders are adjusted to properly support the work in such position requiring minimum movement of the torch, additional supports I2 maybe placed under the intermediate portions of the work to effectively support it against any shifting movement. As illustrated herein, the work piece may take the form of a die substantially square in cross section, which when positioned in the work holder presents one corner I3 which is to be flame' hardened uppermost between a pair of adjacent side faces |4 and i5. It is to be particularly noted that these adjacent faces I4 and I5 need not be at right angles to each other throughout the length of the work piece, but their angles may vary through the length of the work piece, from less than 90 degrees, all the way up to 180 degrees without necessitating stopping and resetting of the apparatus or the changing of torch tips as the apparatus moves from one end of the work to the other. In addition, thev work piece may possess curvatures in horizontal planes as shown in Fig. 2, or in vertical planes as shown in Figl; the apparatus being adaptable to effectively operate upon any contours whatsoever. Y

Upon the beams l, are bolted a pair of pedestal feet I6 for a pair of tubular pedestals or uprights Il suitably truss braced with adjustable rods I8 extending from cap pieces to the base, as shown in Fig. 3. A pair of vertically spaced adjustable brackets 9 are lslidable upon each upright post I1. A threaded rod passes vertically through each pair of these adjustable brackets and is journaled at its top in the cap piece and at its bottom in the foot piece IB where it is provided with a worm wheel 2| meshing with a worm 22 provided at each end of a. rod 23 extending through each of the foot pieces I6 and terminates in a squared end whereby a crank may be applied to either end for rotating the shaft 23 and the screws 20 to vertically adjust the pair of brackets work to be performed. A includes a pair of links 24 and 25 pivotally connected together as at 26 and the joint is provided with thrust bearings 26. The its inner end on a vertical axis 21 between the vertically aligned adjustable bracket |9 whereby the two links may freely swing and pivot in a. horizontal plane. The pairs of links 24 and 25 at opposite sides of the apparatus are caused to move in unison by means of a rod 28 connecting the pivots 26.

A track supporting bracket or link 29 is pivoted on a, vertical axis to the free end of each link and suitable thrust bearings 30 are provided to ease the pivoting of the joint. A track 3| extending the entire length of the bed of the apparatus is secured at opposite ends to the two brackets 29 and thus the two arms 25, rod 28 and track 3|, 'form a parallelogram structure which is bodily movable horizontally in any direction. The uplink A24 is pivoted at surface of track 3|.

. 3| to prevent any elevation to lit the particular parallelogram structure f -justed across the bed of two longitudinals of a parallelogram, the side links of which areV constituted by the links 25 -whereby thevtrack 3| can move back and forth and sideways in any horizontal plane to which it is adthe apparatus. 'Ihis is indicated in dotted lines in Fig. 2.

Mountedto bepropelled lengthwise upon the track 3| and lengthwise of the work therebeneath, is a flame treating torch carriage 34 having a pair of rollers 35 on horizontal axes at opposite ends of the carriage to ride in the V-shaped tread Thus, the'entire weight of the carriage is disposed upon the track 3I and the carriage is prevented'from tipping over to its heavier side by the provision of a pair of guide rol1ers36 mounted in vertical axes at the lower edge of the carriage engaging the vertical outer face of the lower guide rail 33. This carriage is provided with a horizontal shelf 38 overhanging the track 3| for the support of a reversiblevariable speed electric motor 39 set on the platform diagonally across the track so that the power is delivered from one end on one side of the track through a Boston coupling 40 to a shaft extend- .f

ing into a substantially circular gear housing 4| which has its center disposed to one side of the track 3l asbest shown in Fig. 2. A suitable worm driven from the motor meshes with a worm wheel 42 keyed to a vertical shaft 43, depending through a suitable bearing to the right side of the track 3| and to a point opposite the same where itis provided with a spur gear 44 for meshing with the track rack 32 for constantly propelling the carriage 34 across the bed of the apparatus and the work disposed thereon. The operator may hold the track 3| with his 'hands or otherwise suitably biasthe pantographic system 24, 25, 28, tendency of the track from being moved back through the carriage 34 rather than the carriage being moved longitudinally upon the track. The weight of the housing 4I and motor 39 to one side of the track 32 is somewhat counterbalanced by the supporting structure on the opposite side .of the track for the torch mechanism.

For supporting the torch laterally of the carriage, the latter is provided with a circular chamber having an annular shoulder 50 against which abuts the flange of a hub 5| carrying a worm wheel 52. The hub 5| is secured toand rotates with a laterally extending housing 53 made up of diagonally extending shaft 56 having a hand per face of the track 3| is provided with a V tread crank 5`| by which the hub 5| and torch support are rotated or oscillated upon a horizontal axis with the anges 5|) and 54 forming the bearings for such movemen This angular adjustment is provided for initially setting the torch at the most advantageous angle to the work to be performed in order that the torch will only have to execute the minimum movements during its automatic travel. The lateral torch support 53 is provided with a central horizontal chamber 54' to house a wormwheel 55' keyed to a quill or sleeve 56' having an annular shoulder 5l to support it for rotation with the worm wheel within the support 53. A worm shaft vided with`a handle 59 whereby the quill 56 can be manually the torch in a horizontal plane.

A gas mixing chamber. polygonal in cross section, is vertically adjustable throughl the quill 56 meshing with wheel 55' is prooscillated .on a vertical axis to turn usually air and acetylene gas.

88 meshing with cent face 82 which is and suitable air and gas pipes 8 I each individually asvaaoe controlled by a valve, lead into the mixing chamber to supply the same with a The lower end of this chamber 68 is provided with a coupling 61 for connecting with a T-connection 68 which is provided with a pair of oppositely extending arms 88. from' the free end of each of which depends a standard 18 having a roller 1| in its lower end to engage and roll upon the uppermost corner of the work. Thus, it will be seen that this mounting of themixing chamber equips it with means lfor automatically compensating or following the vertical variations in elevation of the work vpiece Il. Extending transversely through the standards 10 are a pair of aligned screws 12 which pass axially into opposite ends of a pivot pin 13 forming the horizon tai common axis or tions 14 and 15 of the torch.

Each torch section is supplied with a combustible gas mixture through a resilient copper coiled conduit 18 having a couple of turns between its ends, one end of which is connected to the torch 14 while the opposite end of the coil is connected.

with the T-connection 68. A similar coil 11 is provided for supplying the torch section 18 with a combustible mixture and it will be seen, due to the pivotal arrangement of the torch sections that these coils normally resiliently urge the two sections 14 and 15 of the torch to swing toward each other on their common pivot 13` and are resiliently pressed against the work. The free ends of the torch sections are provided with work engaging rollers 18 whichare adapted to engage with opposite adjacent faces I4 and I6 of the work piece defining the corner I8 of the work to be treated or flame hardened. With this construction, it will be obvious that the angularity of the two torch sections 14 and 15 will automatically vary according to the variance of the angle between the two work faces |4 and I8, thereby maintaining uniformity of distance between the work and torches as well as a substantial 90 degree disposition of the jets of the torches with the work. The torch section 14 is provided with a bifurcated `upper end 18 which straddles the projection 80 at the upper end of torch lsection 1l so that both torch bodies are arranged in the same vertical plane and will cover corresponding portions of the work surfaces on oppositelsides of the Iworkl corner. Each torch section is provided with a bottom. surface 8| parallel with the face o! the work against which it is directed, and an angular vadiaarrangedat approximately an angle of 20 degrees l treated. Extending throughthe bottom face 8| are two rows of gas iet orifices 88 which are drilled with a number 6'1 drill lines of openings are staggered with each other to form as nearly a ribbon-like terrupted flame asis possible with separated ori; I i

flces. The inclinedface 82 of the torch section `hinge joint for the two sec-V is provided withl a line of orifices 84 which is parallel to the lines of orifices 83. However; the orifices 84 arearranged normal to the inclined face and are preferably made with a No, 10 drill to spray the quenching or cooling fluid upon the work in a direction pointing somewhat away from the orifices 83 and -upon the work just previously heated by the impingement of the flames from the orifices 88. Each torch section is provided with a gas inlet union 88 to be connected with;

its respective gas conduit 16 or 11 to supply combustible gas to the orifices 83. A quenching iiuid is led to each torch section through a coupling.

to the work face being and the orices in the tending lengthwise of torch section.

to an internal chamber supplying the orifices 84.l

Each torch Asection is also provided with coolant inlets and outlets 81 and 88 for circulating a coolant through a cooling chamber in each section.

ther description thereof isunnecessary.

The torch shown in Figs. 16 to 24 inclusive is not composed of a pair of relatively movable sections as in Figs. '1 to 15, but the sections14 and 15 are rigidly connectedtogether' ata 90 degree angle and have a common gas supply nozzle for supplying both sections. This type of torch is designed to treat adjacent surfaces which are arranged at a constant upon such surfaces and to maintain the jets at an angle of degrees to the work, a triangular slider block-8| with its apex lowermost to engage the work is recessed to receive the free end of each torch section, and the two slider blocks are clamped on the ends of the 'torch sections with V-shaped bolts 82 and nuts. Partsof this type of `torch corresponding to the type shown in Figs.

'I t0 l5 are designated with primed corresponding reference numerals. The only differences between the two, are' that the gas and coolant chambers of the two torch sections 14' and 15' are connected and supplied with common supply pipes since the torch `sections are integrated, and in place of the round gas orifices 88 of Figs. 7 to 15, the sections'14 and 15' areA provided with means .for creating ribbon-like `gas flames.

shown in Figs. 18, 21, 23 and 24, this is accomplished by providing eachvsection with a groove 88 extending longitudinally of the face 8 of each section to cut into the internal gas chamber of the-section and securing in such groove a flame bar 84 with rectangular notches 86 in opposite edges thereof. These notches are .025 of an inchin width and are spaced the same distance apart to form small rectangularorifices 88 and provide for individual ribbon-likejets and flames which merge lengthwe of the torch section to provide a substantially continuous ribbon4like flame exnotches or'grooves Il at opposite sides of the name bar 84 are staggered relative to one'another to provide for an uninterrupted and continuous flame to be moved or swept across. the face of the work. The flame bar is preferably silver soldered in its groove as are all otherA Joints between the parts where leakage is to be precluded.`

In Figs. 26 to'32 inclusive is illustrated a form of torch for name hardening concave tube dies as shown in Fig. 25. Thel bottom surface of the torch is provided with a longitudinally extending horizontal portion |00, a 10 degree inclined portion |8l on' one side thereof, and a 20 degree'inclined portion |82 on the other side thereof. This longitudinal horizontal portion |80 has its medial.

with a protuberance |03 making Since the construction of' the passages through the torch sections is well known, a furunvarying angle of ,90 degroes. In order to cause the torch sections to ride As best l These y 'zontal middle face |05 with a work being treated.

rst an angle of 4,5 degrees with the horizontal face and then an angle of 30 degrees therewith to terminate in a rib-shaped tip |04 normal to the horizontal plane. The face of this tip has a horigas oriiice |06 normal thereto, and 12 degree faces on opposite sides of the middle face with gas orices |01 normal thereto. The 30 degree faces of the torch closely adjacent the tips |04 have lgas orifices |08 normal thereto. There are two lines of these orices arranged transversely of the tip as shown in Fig. 3l. Thus the torch protuberance |03 has a crosssection somewhat semi-circular to conform somewhat to the semi-circular concavity of the tube die |50 and its gas passages substantially radiate from a longitudinally extending gas passage |09 which is supplied by a parallel passage H and connecting ports The passage H0 is intersected by a pair of parallel gas passages H2 extending longitudinally above the horizontal portion |00 of the torch so that rows of gas orices H3 can extend normal to such passages and break through the horizontal portions |00 on opposite sides of the protuberance |03. The passages ||2 are fed gas sages H0, both of which communicate vwith a bore H5, fed from a gas connecting nipple H6. The degree face |02 of the torch is provided with orices normal thereto for spraying a quenching uid in the concavity immediately trailing the gas jets |06, |0'l and |08. Likewise this same face on opposite sides of its middle portion is provided with a row of liquid orifices ||8 to trail the gas orifices il@ and to-supply fluid to quench the heated metal of the die on opposite sides of its concavity. Liquid is applied to the oriiices H7 and H0 by passage ||9 furnished to a nipple |20 from a suitable source of supply. The torch is also provided with a circuitous cooling passage |2| connected at the ends of the circuit with an inlet |2| and an outlet |22 whereby a continuous stream of liquid is kept circulating in the torch to maintain it at proper temperature.

From the foregoing description it is believed that the operation of the apparatus is understood. Various changes in the size, shape and arrangement of partsmay be resorted to Without departing from the spirit of 'the invention or the scope of the appended claims,

I claim:

l. An automatic flame hardening apparatus comprising a track supported to move bodily in a horizontal plane, a carriage propelled lengthwise thereupon, a torch carrier supported by said carriage and mounted on a horizontal axis, a torch suspension member being adjustable lengthwise vertically and oscillatable upon a vertical axis and adapted to be guided by the contour of the work,

and a torch head adapted to engage the work and being mounted upon said suspension member on a horizontal axis to tions and varying angles of the surfaces of the 2. An automatic name hardening apparatus for treating the corner edge of work `comprising a pair of torches pivotally mounted on a common axis adjacent said corner edge and being independently automatically spring urged against adjacent faces voi said corner edge to automatically conformto varying contours and angles of said adjacent faces.

3. .An automatic iiame hardening apparatus for treating the corner edge of Work comprising a pair of associated torchesindependently adjustable to follow varying contours of adjacent surfaces from a pair of parallel pasadapt itself to vertical varia` of work forming said corner edge and each of said torches having a resilient coil with its axis longitudinal of said corner edge for feeding gas to the torches and urging the same into contact with said adjacent surfaces of the work.

4. An automatic flame hardening apparatus for treating a lengthwise corner edge of work cornprising a vertically adjustable torch carrying member having means engaging the corner edge of the work to vary `the elevation of said member according to the elevation of the work as the member is moved lengthwise thereof, and a torch pivotally connected to said member on a horizontal axis longitudinally of the corner and having a roller engaging anadjacent face of the work to swing the torch to the angle of said adjacent face as the torch is moved lengthwise thereof.

5. An automatic flame hardening apparatus comprising a horizontal track and guide rail, said track having a laterally extending rack, a torch carrying carriagehaving a pair of supporting rollers riding upon said track and a guide roller engaging the vertical side of said guide rail, torch supporting means extending laterally from the carriage upon one side of the track, a gear engaging said rack upon the opposite side of the track, and a drive mechanism for said gear disposed upon the last named yside of the track to substantially balance the carriage in monorail fashion upon said track.

6. An automatic ame hardening apparatus comprising a pair of spaced uprights, a pair of pivotally connected links pivotally connected on a vertical axis to each upright, a track support pivotally connected on vertical axes to the free ends of said links, a rod connecting the pivotal connection of the pairs of links causing them to move in unison, a track connecting the track support and being movable in all directions in a hori-q zontal plane, a carriage propelled lengthwise upon said track, and a torch universally supported upon said carriage to engage the work to be guided thereby.

7. An automatic llame hardening apparatus comprising a carriage propelled lengthwise of the Work, a torch holder, a pair of supports depending from said holder, a roller adapted to engage the work, and a torch pivotally suspendedbetween said supports and adapted to engage an adjacent face of the corner of the Work.

8. A ame hardening torch for corner edges of Work comprising a pair of torch bodies, means pivotally connecting said torch bodies together at corresponding ends for substantially free pivotal movement relative to each other, torch guiding means for engaging the work on opposite. sides of the corner edge, and resilient means for urging said torch bodies toward each other whereby to maintain said torch bodies in substantially the same predetermined relationship with respect to the work faces on opposite sides of the corner edge.

9. A flame hardening apparatus comprising a carriermemberl having a gas duct, a torch body having a gas passage, means for connecting the carrier member and torch body for substantially free pivotal movement, and a resilient coiled gas pipe having a normal tendency to uncoil and having one end connected with said duct of the carriermember and the other end connected with said passage in the torch body and tending normally to spring press the body in a predetermined direction, and work engaging means carried by the torch body for positioning the torch body with respect to the work..

mounted in each support aavaaos variations inthe vertical and horizontal profile portions of the work asv the carriage is propelled Valong said track.

rier, torch guide means operatively associated with the torch and engageable respectively with the vertical and horizontal profile portions of a work piece, and means for maintaining said guide means in contact with the work as the carrier traverses said track to thereby move the torch vertically and horizontally in accordance with variations in the verticaland horizontal-profile portions of the work traversed by said torch guide means.v l

ll An automatic flame hardening apparatus comprising a torch carrier, means for supporting said carrier for movement in all horizontal directions, a torch member, means mounting the torch 13. An automatic ame hardening apparatus for treating an irregularly curved work piece comprising 'a torch member having an operating surface disposed substantially parallel to the work face of a work piece and including means engageable withopposed horizontal prole portions of the work piece, means for *propelling said torch lmember in a rectilinear path lengthwise of the member for vertical movement on the torch earrier and for pivotal movement abouta horizontal axis, said ltorch member including torch -guide means engageable with the work, means for maintaining the torch lguide means in contact -with the horizontal and vertical prole portions of the Y work respectively, as the torch carrier is moved lengthwise of the work to thereby move the torch member horizontally and vertically in accordance with variations in the horizontal and vertical profile portions of the work traversed by said guide and resilient means tending to rotatel the horizontal pivot and toward l means. torch member on said the work to thereby maintain the torch member in 4predetermined relationpto said work.

l2.v An automatic Aflame hardening apparatus comprising a pair 'of spaced uprights, a pantographic linkage pivotally supported thereon for movement about 'vertical axes and comprising a plurality of arms pivotally connected at the cori ners of the pantographic linkage, one arm of said linkage constituting a track horizontally movable transversely of a work piece, a carriage propelled lengthwise upon said track and a torch supported ppon said carriage together with means 'for mounting the torch -for relative vertical movement with respect to the carriage, torch guide means operatively associated with said torch means and positioned to engage respectively the vvertical prole portion and opposed horizontal profile portions of the work, means for maintaining said torch guide means in operative engagement with the verticaland opposed horizontal proiile portions'of the work whereby the torch is moved vertically and horizontally in accordance with work piece .and in contact therewith, means for mounting said torch member for horizontal movement transversely of the workpiece and pivotally about a vertical axis and about a horizontal axis disposed lengthwise of and above the work piece, means for maintaining the torch member in c ontact with the work at all times whereby said torch member is moved in all directions horizontally by. guiding contact with the workpiece, and resilient means urging said torch member about said horizontal axis and toward said work whereby said operating face of the torch is maintained at all times substantially parallel to thework face of the work piece. v- Y 7 14. An automatic llame forA treating an irregularly curved work piece com- Y prising taining contact between said work engaging 4porv vertically and spaced means for profile portions of a torch member having anoperatin surface disposed substantially parallel :to the work face of a work piece, said torch member being provided with work engaging means including engaging opposed horizontal the work piece and -means for engaging the vertical profile portion of the work meansl for propelling said torch member in a rec- I tilinear path lengthwise of the work piece and in contact therewith, means for mounting said torch member to move vertically and horizontally of the work piece and pivotally about a vertical axis and Aabout a horizontal airis disposed lengthwise of and above the work piece; means for-maintions of the torch member and the vertical and horizontal p'roiile portions of the work piece at all times whereby said torch member'is moved horizontally in accordance with.

the variations in the vertical and horizontal proiile portions of the work piece as the torch member is moved lengthwise of the work piece and resilient means urging the torch member about said horizontal axis and into contact with the work face whereby said operating face of the torch member is maintained at all times substantially parallel to the workiface o! the work piece.

.hardening apparatus 

